Window coverings of various different configurations are provided to control the amount of light passing through a window, to selectively allow or preclude viewing through the window, and generally to decorate the window. Often windows are surrounded by a frame including a horizontal lintel above vertically oriented sides. It is often desirable that a top rail of a window covering be mounted to the window frame directly below the lintel and between the vertical sides of the window frame. Such mounting has heretofore been generally difficult to achieve requiring a relatively high level of skill and moderately complex mounting hardware. In particular, brackets are typically provided which are fastened with screws or other fasteners to either the lintel or the vertical sides of the window fame directly below the lintel. Installation of the mounting brackets is sufficiently difficult that many home owners choose to utilize window covering installation professionals, rather than performing the installation themselves.
Some attempts to avoid the requirement of installing mounting brackets or similar hardware have only achieved limited success. For instance, the patent to Schumacher (U.S. Pat. No. 5,158,127) teaches utilizing adhesive to secure a top rail of a window covering to the undersurface of the lintel of the window frame. Such mounting is generally only effective for particularly lightweight window coverings. Another attempt to avoid mounting hardware is illustrated by the window shade roller assembly taught by Barettella (U.S. Pat. No. 4,373,569). While Barettella is somewhat effective, the Barettella assembly must necessarily limit compression mounting forces to forces which can be readily exerted by the user installing the window covering. The user of the Barettella invention is not able to hold the ends of the assembly away from the window frame sides for desired positioning without exerting forces on the ends during the entire positioning procedure until the final position for the shade has been selected. Also, the Barettella window shade roller assembly is not readily adapted to facilitating resizing of a length of the window shade roller assembly to fit the particular width of the window in which the window shade is to be mounted. The Barettella assembly is not modular and readily attachable/detachable from the rest of the shade. Rather, it is integrated into other parts of the shade. Accordingly, a need exists for a window covering mounting system which avoids the use of specialized mounting hardware, and which can be easily and readily positioned precisely where desired by a homeowner having limited strength and still securely support window coverings of various different weights where desired within the window frame.